This application claims priority based on Japanese Patent Application No. 11-228419, filed Aug. 12, 1999; Japanese Patent Application No. 2000-40191; filed on Feb. 17, 2000; and on Japanese Patent Application No. 2000-234663, filed on Aug. 2, 2000.
1. Field of the Invention
The present invention relates to a database design system, a database design method, a recording medium, and a display method. More precisely, the present invention relates to a database design system, a database design method, a recording medium, and a display method which automatically create an E-R diagram.
2. Description of the Related Art
An E-R (Entity-Relationship) model database creating operation is performed through each phase of preliminary design phase, detail design phase, and E-R diagram creation phase.
In a normalized database design process, which is mainly for an input-output screen (referred to as xe2x80x9cscreenxe2x80x9d hereafter) and for a form, DA (Data Administrators) and SE (Systems Engineers) take charge of the task of designing. The present situation is that the number of screens/forms is more than 100 or 200 in some cases, and DAs and SEs design all of the screens/forms by handwork. The E-R model database design is described in detail in, for example, xe2x80x9cClient/Server Database Design Techniquexe2x80x9d (SRC Handbook, by Masamni Satoh, the fourth edition published on Oct. 20, 1994).
When E-R diagrams are created by handwork, there has been a problem in that working hours are prolonged remarkably following an increase of the number of formats of screens/forms and thus lowers the production efficiency, or that the quality of the created E-R diagram will be dependent on experience of individual designers.
Moreover, when additional screens or additional forms need to be formed after an E-R diagram is created, DAs or SEs have to be engaged in additional processes by handwork. Since the design method is not specified, there has been another problem in that the additional processes are difficult to be performed and that designs differ according to the designers.
In order to solve these problems, the applicant of the present invention has proposed an E-R diagram design system in which normalization design of a database is worked out automatically by utilizing a computer in a database normalization design and development operation for an RDB (Relational Database).
More precisely, the system classifies screen/form data into key definition data and data items, and creates a temporary entity. The system retrieves the key definition data of each temporary entity, aggregates duplicated entities into one, normalizes the entity (i.e., creates a normalized entity), and specifies a type of each normalized entity. Moreover, the system creates a table showing the correspondence between the normalized entity and each screen/form, and creates an E-R model on the basis of the relationship between each entity in the table and/or stored in memory in advance.
By utilizing this system, an accurate normalization design of a database can be worked out without depending on each designer, so that the production efficiency and the quality can be raised.
However, in the prior art, when a plurality of E-R diagrams created for every business or every organization are integrated (an integrated E-R model generation), when the created E-R diagram is split into every business or every organization (or every business or every organization is extracted from the E-R diagram, i.e., an extracted E-R model generation), or when an E-R diagram is created for every screen/form in order to create a program specification, there has been a problem with this system in that whole steps of the normalization design of the database have to be done over again from the very beginning even though E-R diagrams have been created in the past, so that the production efficiency is inferior.
Moreover, in the prior art, when data generated in the process of design of the E-R diagram need to be altered in order to create an E-R diagram after addition or deletion of a screen/form, modification of the contents, or the like, there has been a problem with the above-described system in that generation process of the data has to be done over again from the very beginning, so that the production efficiency is inferior.
Further, when a screen/form needs to be deleted, a user designates entities, which are used only on the screen/form to be deleted, from among the entities used on the screen/form, and then the system deletes the designated entities and the relationship between these entities to create again an E-R diagram. Therefore, there has been a problem with the system in that an accurate normalization design of a database may not be worked out when the user mistakenly designates entities used on other screens.
Further, in the prior art, processing objects are screens/forms, so that the system has not corresponded to a functional specification, in which operations between data items define other data items, frequently used in business. Furthermore, in the prior art, each type of data cannot be effectively displayed during an E-R diagram creation process. Thus, the E-R diagram creation process has been lacking in user-friendliness.
The present invention is provided so as to solve the aforementioned problems, and an object of the present invention is to provide a database design system, a database design method, and a recording medium, in which a normalization design operation for an RDB can be performed corresponding to a functional specification as well as a screen/form, and integration of and extraction from E-R diagrams created after a database normalization design operation, and addition and deletion of targeted screens, forms and/or functional specifications to be processed can be performed efficiently and accurately, so that the production efficiency and quality can be improved. Further, another object of the present invention is to provide a display method that can effectively display each type of data when an E-R diagram is created.
In order to achieve the aforementioned objects, a first aspect of the present invention is a database design system utilizing an E-R model including: a temporary entity creation section for creating a temporary entity by classifying a plurality of data including key definition data and data items corresponding to the key definition data into the key definition data and the data items corresponding to the key definition data; a normalized entity creation section for creating a normalized entity by aggregating the temporary entities, if any, which have a common key definition data therein, into one entity; a setting section for setting an entity type for the normalized entity; a first table creation section for creating a first matrix table showing the correspondence between the normalized entity created by said normalized entity creation section and the data; a second table creation section for creating, for each of the data, a second matrix table showing the relationship between the normalized entities which belong to the data, on the basis of the first matrix table and the relationship between the normalized entities based on a preset entity type; and an E-R diagram creation section for creating an E-R diagram on the basis of the second matrix table created for each of the data by said second table creation section.
In accordance with the first aspect of the present invention, the temporary entity creation section classifies the plurality of data, which include the key definition data and the data items corresponding to the key definition data and are input by the input section, into the key definition data and the data items corresponding to the key definition data to create a temporary (or unnormalized) entity.
In a second aspect of the invention, the system further includes an input section for inputting a plurality of data which includes key definition data and data items corresponding to the key definition data. Data may be input to the database design system with the input section, directly or via a network or the like. Further, the data may be data for/on a screen, a form or a functional specification. Moreover, when a plurality of identical key definition data or data items are included in the same data such as in a functional specification, for example, the temporary entity creation section may aggregate the identical key definition data or the data items in each of the data into one (i.e., remove duplication), and then create a temporary entity.
The normalized entity creation section performs aggregating operation (so-called normalization operation) to aggregate the temporary entities, if any, which have a common key definition data therein, among the created temporary entities into one entity, and creates a normalized entity. An entity type of the created normalized entity is then set by the setting section.
Moreover, the first table creation section creates a first matrix table showing the correspondence between the normalized entity created by the normalized entity creation section and the data. What can be understood from the first matrix table is that with which data each normalized entity is corresponding (belongs to), in other words, to which data the temporary entities aggregated for each normalized entity have belonged. It can also be understood which normalized entity belongs to each screen.
The second table creation section creates, for every data, a second matrix table showing the relationship between the normalized entities on the basis of the first matrix table and a table which predetermines the relationship between entities according to their entity types. The E-R diagram creation section creates an E-R diagram on the basis of the second matrix table. In such a manner, a so-called database normalization design operation may be performed to generate the relationship between the normalized entities, and then to create E-R diagrams.
At this time, since the second matrix table is created for each of the data, in a third aspect of the present invention, the E-R diagram creation section can easily create an E-R diagram either on the basis of at least one of the data or on the basis of a combination of two or more input data. That is, it is possible to create any of an E-R diagram on the basis of all of the data, an E-R diagram for every input data (a partial/sectional E-R diagram), and an E-R diagram on the basis of any data combination from among all of the data (an extracted E-R diagram).
A fourth aspect of the present invention is a database design system according to the first aspect, wherein when a command to integrate a plurality of E-R diagrams created by the E-R diagram creation section is entered, the normalized entity creation section aggregates the normalized entities, if any, which have a common key definition data therein, into one entity at the time of generation of each E-R model.
In the fourth aspect of the present invention, when a plurality of E-R diagrams created by the E-R diagram creation section are integrated, the normalized entities having a common key definition data among the normalized entities in the plurality of E-R diagrams created by the normalized entity creation section are aggregated into one entity. That is, the normalized entity creation section performs the normalization operation targeted over the normalized entities which have been used in creating different E-R diagrams, and eliminates the duplication of the normalized entities. On the basis of the results, the first matrix table is created by the first table creation section, and the second matrix table is created by the second table creation section on the basis of the created first matrix table. The E-R diagram creation section may integrate a plurality of E-R diagrams to create an integrated E-R diagram by creating an E-R diagram on the basis of the second matrix table.
A fifth aspect of the present invention is a database design system according to the first aspect, further including an altering section for altering at least one of the correspondence between the normalized entity in the first matrix table and the input data, the relationship between the normalized entities in the second matrix table, the entity type of the normalized entity, and the correspondence between the key definition data and the data item which form the normalized entity.
In accordance with the fifth aspect of the present invention, at least one of the correspondence between the normalized entity in the first matrix table and the data, the relationship between the normalized entities in the second matrix table, the entity type of the normalized entity, and the correspondence between the key definition data and the data item which form the normalized entity is altered by the altering section. Accordingly, the system can manage to add and/or delete data, to modify contents, and the like.
For example, the correspondence between the normalized entity and the data (i.e., the first matrix table created by the first table creation section) can be altered by the altering section on the basis of addition and/or deletion of data, contents modification of data, and the like.
The relationship between the normalized entities (i.e., the second matrix table created by the second table creation section) can also be altered by the altering section on the basis of addition and/or deletion of data, contents modification of data, alteration of the entity type of the normalized entity, and the like.
Moreover, when an improper entity type is set by the setting section, the entity type of the normalized entity can be easily altered to the correct entity type by the altering section.
Further, the altering section can alter the correspondence between the key definition data and the data items which form the normalized entity on the basis of addition and/or deletion of data, contents modification of data, and the like.
A sixth aspect of the present invention is a database design system according to the fifth aspect, wherein the altering section includes: a first decision section for deciding, when a command to delete the data is entered, whether deletion of the normalized entity included in the target data to be deleted is possible or not; and a first deleting section for deleting the data when the first decision section decides that deletion of the normalized entity is impossible, and for deleting the data and the normalized entity when the first decision section decides that deletion of the normalized entity is possible; wherein the altering section alters correspondence between the normalized entity in the first matrix table and the data when the data, or the data and the normalized entity are deleted by the first deleting section.
In accordance with the sixth aspect of the present invention, the altering section is provided with the first decision section and the first deleting section. When the command to delete the data is entered, the first decision section decides whether deletion of the normalized entity corresponding to the target data to be deleted (the data designated by the delete command for deletion) is possible or not. The normalized entities corresponding to the target data to be deleted can be extracted from the first matrix table. The first deleting section deletes only the target data to be deleted when deletion of the normalized entity is impossible, and deletes the normalized entity along with the target data to be deleted when deletion of the normalized entity is possible. The altering section alters the correspondence between the normalized entity and the data in the first matrix table on the basis of the results of the deletion, thereby enabling the first matrix table to be altered (modified) easily and efficiently according to deletion of data.
At this time, in a seventh aspect of the present invention, the first decision section may decide that deletion of the normalized entity is possible when the normalized entity corresponding to the target data to be deleted corresponds only to the target data to be deleted. Accordingly, the target data to be deleted as well as the normalized entity associated only with the target data to be deleted can be deleted from the first matrix table.
For example, as in an eighth aspect of the present invention, the system may further include a first storage section for storing the number of data to which the normalized corresponds, wherein when a command to additionally input the data is entered, the first decision section increments the number, stored in the first storage section, of the normalized entity corresponding to the target data to be added, and when a command to delete the data is entered, the first decision section decrements the number, stored in the first storage section, of the normalized entity corresponding to the target data to be deleted, and the first decision section decides that deletion of the normalized entity is possible when the number becomes xe2x80x980xe2x80x99.
That is, the first storage section stores the number of data (referred to as xe2x80x9cthe utilization numberxe2x80x9d hereafter) with which each normalized entity is associated (i.e., utilized). The utilization number is incremented or decremented according to addition or deletion of data by the first decision section, and always updated to the up-to-the-minute value. Accordingly, when the first decision section decrements the utilization number of the normalized entity corresponding to the target data to be deleted according to the deletion of the data and the number becomes xe2x80x980xe2x80x99, the first decision section can decide that the normalized entity is only corresponding to the target data to be deleted, so that deletion of the normalized entity is possible.
A ninth aspect of the present invention is a database design system according to the fourth-aspect, the altering-section includes: a second deleting section for deleting the relationship between the entities in the second matrix table when a command to delete the relationship between the entities in the data is entered, and wherein the E-R diagram creation section includes: a second decision section for deciding whether deletion of a connecting line, which indicates the relationship between the entities deleted by the second deleting section, from the E-R diagram is possible or not; and a third deleting section for deleting the connecting line indicating the relationship between the entities from the E-R diagram when the second decision section decides that deletion of the connecting line is possible.
In accordance with the ninth aspect of the present invention, in the altering section, when the command to delete the relationship between the entities is entered in the case in which the need arises to delete the normalized entity due to deletion of data or modification of contents, or in which an unnecessary relationship between normalized entities exists, the second deleting section deletes the relationship between the normalized entities from the second matrix table.
In the E-R diagram creation section, when the relationship between the normalized entities is deleted by the second deleting section, the second decision section decides whether deletion of the connecting line between the entities from the E-R diagram is possible or not. When the second decision section decides that deletion of the connecting line is possible, the third deleting section deletes the connecting line between the entities from the E-R diagram. In such a manner, the E-R diagram can be altered (modified) easily and efficiently by altering (modifying) the second matrix table according to deletion of data, contents modification, or deletion of unnecessary relationship between normalized entities.
At this time, as in a tenth aspect of the present invention, the second decision section may decide that deletion of the connecting line indicating the relationship between the entities in the E-R diagram is possible, when the relationship between the entities deleted by the second deleting section exists only in the data related to the deleted relationship between the entities.
Accordingly, when the relationship between the normalized entities existed only in one data is deleted, the connecting line showing the relationship between the normalized entities can be deleted from the E-R diagram, and when the relationship between the deleted entities exists in other data, the connecting line showing the relationship between the normalized entities on the E-R diagram can be remained.
For example, as in an eleventh aspect of the present invention, the system may further include a second storage section for storing the number of data to which the relationship between the entities belongs, wherein when a command to add the relationship between the entities is entered, the second decision section increments the number, stored in the second storage section, corresponding to the target relationship between the entities to be added, and when a command to delete the relationship between the entities is entered, the second decision section decrements the number, stored in the second storage section, corresponding to the target relationship between the entities to be deleted, and the second decision section decides that deletion of the connecting line indicating the relationship between the entities in the E-R diagram is possible when the number becomes xe2x80x980xe2x80x99.
That is, the second storage section stores the number of data to which each relationship between entities belongs (referred to as xe2x80x9cthe relationship numberxe2x80x9d hereafter). The relationship number is incremented or decremented according to addition or deletion of the relationship between the entities by the second decision section, and always updated to the up-to-the-minute value. Accordingly, when the second decision section decrements the relationship number of the relationship between the entities according to the deletion of the relationship between the entities and then the number becomes xe2x80x980xe2x80x99, the second decision section can decide that the relationship between the entities exists only in the data corresponding to the target relationship between the entities to be deleted, so that deletion of the connecting line showing the relationship between the entities on the E-R diagram is possible.
A twelfth aspect of the present invention is a database design system according to the fourth aspect, wherein when a command to alter the entity type of the normalized entity is entered, the altering section alters the entity type of the normalized entity, retrieves data corresponding to the normalized entity from among the data by referring to the first matrix table, and alters, on the basis of the alteration of the entity type, the relationship between the normalized entities belonging to the retrieved data.
In accordance with the twelfth aspect of the present invention, when the altering section alters the entity type of the normalized entity, it looks up the first matrix table, retrieves the data with which the normalized entity is associated from among the data, and alters the relationship between the normalized entities belonging to the retrieved data. Accordingly, alteration. of the relationship between the normalized entities due to the alteration of the entity type can be performed accurately, and any omissions of alteration for the relationship between the normalized entities can be prevented.
A thirteenth aspect of the present invention is a database design system according to the fourth aspect, wherein the altering section includes: a third decision section for deciding, when a command to delete the data is entered, whether deletion of at least one of the key definition data and the data item included in the target data to be deleted from the key definition data and the data item which form the normalized entity is possible or not; and a fourth deleting section for deleting at least one of the key definition data and the data item included in the target data to be deleted when the third decision section decides that deletion is possible.
In accordance with the thirteenth aspect of the present invention, the altering section includes the third decision section and the fourth deleting section. When the command to delete the data is entered, the third decision section decides whether deletion of at least one of the key definition data and the data item included in the target data to be deleted is possible or not. The key definition data and the data item which are decided to be capable of deletion by the third decision section are deleted from the key definition data and the data item forming the normalized entity by the fourth deleting section. In such a manner, the correspondence between the key definition data and the data item which form the normalized entity can be altered (modified) easily and efficiently according to deletion of data.
At this time, as in a fourteenth aspect of the present invention, the third decision section may decide that deletion of at least one of the key definition data and the data item possible when at least one of the key definition data and the data item included in the target data to be deleted is included only in the target data to be deleted. Accordingly, only the key definition data and the data item included in the target data to be deleted can be deleted from among the key definition data and the data items forming the normalized entities.
For example, as in a fifteenth aspect of the present invention, the system may further include a third storage section for storing the number of data including the same key definition data, and the number of data including the same data item, wherein when a command to additionally input the data is entered, the third decision section increments the number, stored in the third storage section, of the key definition data and of the data item included in the target data to be added, and when a command to delete the data is entered, the third decision section decrements the number, stored in the third storage section, of the key definition data and of the data item included in the target data to be deleted, and the third decision section decides that deletion of the key definition data or the data item is possible when the number becomes xe2x80x980xe2x80x99.
That is, the third storage section stores the number of data which includes the same key definition data, and the number of data which includes the same data item (i.e., the utilization number of each key definition data and the utilization number of each data item). These utilization numbers are incremented or decremented by the third decision section according to addition or deletion of data, and always updated to the up-to-the-minute values. Accordingly, when the third decision section decrements the utilization number of the key definition data or that of the data item included in the target data to be deleted according to the deletion of data, the third decision section can decide that the key definition data or the data item whose utilization number becomes xe2x80x980xe2x80x99 is only corresponding to the target data to be deleted, so that deletion of the key definition data or the data item is possible.
A sixteenth aspect of the present invention is a database design system according to the fourth aspect, wherein the E-R diagram creation section modifies the E-R diagram on the basis of the results of alteration performed by the altering section, and give notice of portions of the E-R diagram which have been modified.
In accordance with the sixteenth aspect of the present invention, since the E-R diagram created before alteration is modified by the E-R diagram creation section on the basis of the results of alteration performed by the altering section and the modified parts are informed, users can easily grasp the modified parts. In particular, in the case of a partial E-R diagram used as a program specification for practically constructing a DBMS (Data Base Management System), users can easily understand which part of the program needs to be modified and how it should be modified from the informed modified parts, thereby reducing the time required for a program modification operation.
A seventeenth aspect of the present invention is a database design system according to the first aspect, wherein the temporary entity creation section includes: a master file creating section for creating a master file by registering the key definition data and the data items corresponding to the key definition data of the created temporary entities; a retrieval section for retrieving a data item, which does not correspond to any key definition data even though the data item is the same as the one registered in the master file with a key definition data, by referring to the master file; and a retrieval results notification section for giving notice of the results of retrieval.
In accordance with the seventeenth aspect of the present invention, the temporary entity creation section includes the master file creating section, the retrieval section, and the notification section.
The temporary entity creation section classifies the data into the key definition data and the data items corresponding to the key. definition data to create a temporary entity, and the master file creating section registers the key definition data and the data items corresponding to the key definition data of the created temporary entity into the master file.
Moreover, the retrieval section retrieves a data item, which is not corresponding to any key definition data even though the data item is the same as the one registered in the master file along with a key definition data. The retrieved data item is informed by the notification section. Users decide that the informed data item is a data item forgotten to be classified (or mistakenly classified), and can classify it again, so that a temporary entity can be created properly.
An eighteenth aspect of the present invention is a database design system according to the first aspect, wherein the temporary entity creation section classifies unclassified additional input data into their key definition data and the data items corresponding to the key definition data by referring to the already-created/existing normalized entities, and creates a temporary entity.
In accordance with the eighteenth aspect of the present invention, when the data are additionally input, the temporary entity creation section classifies the additional input data into the key definition data and the data items by referring to the existing normalized entities to create a temporary entity. After normalized entities have been created for the unclassified data by the normalized entity creation section, data may be newly added or there may be, in a case where a large amount of data is to be processed and normalized entity creation processing has already been performed on a part of the data, the rest of the data, or the like. Accordingly, the time required for the data to be added, or the time required for processing the large amount of data, can be reduced.
A nineteenth aspect of the present invention is a database design system according to the seventeenth aspect, wherein the normalized entity creation section aggregates a,temporary entity, which has the same key definition data as that of,one of the existing normalized entities into the one existing normalized entity whose key definition data is the same, and turns a temporary entity having a key definition data different from those of the existing normalized entities into a new normalized entity.
In accordance with the nineteenth aspect of the present invention, when the data is additionally input or when, in the case where there is a large amount of data to process and a part of the data has already been processed, the rest of the data is processed, or the like, the normalized entity creation section compares the key definition data of the temporary entity newly created from the added data, remaining data or the like with the key definition data of the existing normalized entity. When the key definition data are the same, the temporary entity is aggregated with the existing normalized entity. Only when the key definition data are different, the temporary entity is turned into a new normalized entity. Accordingly, the time required for the data to be added can be reduced.
In this case, in a twentieth aspect of the invention, an automatic classification notification section may also be provided. The automatic classification notification section gives notification of the temporary entity that has been automatically classified, with reference to existing normalized entities, or of the normalized entity with which the temporary entity has been aggregated.
A twenty-first aspect of the present invention is a database design system according to the first aspect, further including a manual correction section and a status notification section. The manual correction section is for manual correction of correspondence relationships of key definition data and data items. The status notification section gives notification of the status of corrections made by the manual correction section.
In accordance with the twenty-first aspect of the present invention, correspondence relationships of key definition data and data items can be manually corrected by the manual correction section. Notification of the status of these corrections is given by the status notification section. Thus, the user can easily ascertain where corrections have been made.
A twenty-second aspect of the present invention is a database design system according to the first aspect, further including a consistency decision section and an inconsistency notification section. The manual addition/deletion section implements manual addition or deletion of a normalized entity or, in the data, a key definition data or a data item. After an addition or deletion by the manual addition/deletion section, the consistency decision section decides. whether correspondences between the data and the normalized entities have been conserved or not. If the consistency decision section detects an inconsistency, the inconsistency notification section gives notification of the inconsistency.
In accordance with the twenty-second aspect of the present invention, manual addition or deletion of key definition data or a data item at the data can be done at the manual addition/deletion section. Further, manual addition or deletion of a normalized entity can be done at the manual addition/deletion section. After the addition or deletion by the manual addition/deletion section, the consistency decision section determines whether consistency has been conserved in the data and the normalized entities subsequent to the addition or deletion. If there is an inconsistency, notification is given by the inconsistency notification section. Accordingly, the user can identify an inconsistency easily. The user can then perform an addition or deletion with the manual addition/deletion section, so as to eliminate the inconsistency and facilitate consistency.
A twenty-third aspect of the present invention is a database design system according to the first aspect, further including a division/integration section, which performs division or integration of the normalized entities.
In accordance with the twenty-third aspect of the present invention, the normalized entities can be split or joined by the division/integration section. Thus, access time to the database, when the DBMS is constructed and operated in practice, can be shortened.
A twenty-fourth aspect of the present invention is a database design system according to the first aspect, wherein the first matrix table creation section creates, in addition to the first matrix table, a third matrix table showing, for each of the normalized entities, the correspondence between the key definition data and data item which form the normalized entity, and the data.
In accordance with the twenty-fourth aspect of the present invention, the first matrix table creation section also creates the third matrix table which shows, for each of the normalized entities, the correspondence between the key definition data and data item, forming the normalized entity, and the data. It is possible to understand, based on the third matrix table, as to which data to which the key definition-data and data item which form each entity correspond (belong). As a result, so-called data life cycle analysis is facilitated.
A twenty-fifth aspect of the present invention is a database design system according to the first aspect, wherein the second table creation section classifies the normalized entity into a normalized entity for a header part and a normalized entity for a detail part in which repetitive items in the data are listed, and creates the second matrix table by determining the relationship between the normalized entities for the header part, the relationship between the normalized entities for the detail parts, and the relationship between the header part and the detail part.
In accordance with the twenty-fifth aspect of the present invention, the normalized entity is classified into the normalized entity for the header part and the normalized entity for the detail part, and then the relationship between the normalized entities for the header parts, the relationship between the normalized entities for the detail parts, and the relationship between the header part and the detail part are sought for creating the second matrix table. That is, the relationship between each normalized entity for the header part and each normalized entity for the detail part can be omitted, so that the time required for the second matrix table to be created can be reduced.
A twenty-sixth aspect of the present invention is a database design system according to the first aspect, further including a display control section. The display control section displays the data, the normalized entities, the first matrix table, the second matrix table and the E-R diagram.
In accordance with the twenty-sixth aspect of the present invention, because the display control section can display the data, the normalized entities, the first matrix table, the second matrix table and the E-R diagram, the user can check the same.
For example, the display control section may display the data and the normalized entities along with the first matrix table created by the first matrix table creation section, the second matrix table created by the second matrix table creation section, or the E-R diagram created by the E-R diagram creation section. Accordingly, the user can easily check whether results of the creation of the first matrix table, the second matrix table and the E-R diagram are suitable.
In another example, the display control section may arrange the data in order of identification numbers assigned to each data, or separated into previously assigned groups. A portion of the data is designated to be processed by the normalized entity creation section. The normalized entity creation section processes the designated data and newly created normalized entities are arranged adjacent to the data.
When the display control section displays the data, the key definition data and data items included in each data are displayed in a single display frame assigned to that data. In addition a data title is displayed adjacent to the data frame.
In a thirty-second aspect of the present invention, a database design method utilizing an E-R model includes the steps of creating a temporary entity from a plurality of data including key definition data and data items corresponding to the key definition data by classifying the data into the key definition data and the data items corresponding to the key definition data; creating a normalized entity by aggregating the temporary entities, if any, which have a common key definition data therein, into one entity; setting an entity type for the normalized entity; creating a first matrix table showing the correspondence between the normalized entity and the data; creating, for each data, a second matrix table showing the relationship between the normalized entities, which belong to the data, on the basis of the first matrix table and the relationship between the normalized entities based on the preset entity type; and creating an E-R diagram on the basis of the second matrix table created for each data.
In accordance with the thirty-second aspect of the present invention, the temporary entity is created by classifying the plurality of input data including the key, definition data and the data items corresponding to the key definition data into the key definition data and the data items corresponding to the key definition data. Aggregating operation (so-called normalization operation) is performed to aggregate the temporary entities, if any, which have a common key definition data therein, among the created temporary entities into one entity, and to create a normalized entity. The entity type of the created normalized entity is then set. Moreover, the first matrix table showing the correspondence between the created normalized entity and the data is created, and the second matrix table showing the relationship between the created normalized entities is created on the basis of the first matrix table and a table which predetermines the relationship between entities according to their entity type. The E-R diagram is created on the basis of the second matrix table. In such a manner, a normalization design operation for a database is performed, and the E-R diagram can be created.
Further, by creating the second matrix table for every data, an E-R diagram either on the basis of at least one of the plurality of data or on the basis of the combination of two or more data can easily be created.
As with the first aspect, the plurality of data including the key definition data and the data items corresponding to the key definition data may be input directly or via a network or the like. Moreover, this data may be data for/on a screen, a form, or a functional specification.
In accordance with a thirty-third aspect of the present invention, at least one of the correspondence between the normalized entity in the first matrix table and the data, the relationship between the normalized entities in the second matrix table, the entity type of the normalized entity, and the correspondence between the key definition data and the data item which form the normalized entity may be alterable. Accordingly, addition and/or deletion of data, contents modification of data, and the like can be processed.
In a thirty-fourth aspect of the present invention, a computer readable recording medium is provided on which a database design program for designing a database utilizing an E-R model has been recorded. The database design program creates a temporary entity by classifying a plurality of data, which include key definition data and data items corresponding to the key definition data, into the key definition data and the data items corresponding to the key definition data, creates a normalized entity by aggregating the temporary entities, if any, which have a common key definition data therein, into one entity, sets an entity type of the normalized entity, creates a first matrix table showing the correspondence between the normalized entity and the data, creates, for each data, a second matrix table showing the relationship between the normalized entities which belong to the data, on the basis of the first matrix table and the relationship between the normalized entities based on a preset entity type, and creates an E-R diagram on the basis of the second matrix table created for each data.
In accordance with the thirty-fourth aspect of the present invention, the database design program for creating the E-R diagram has been recorded on the computer readable recording medium. According to the program, the temporary entity is created by classifying the plurality of data including the key definition data and the data items corresponding to the key definition data into the key definition data and the data items corresponding to the key definition data. Aggregating operation (so-called normalization operation) is performed to aggregate the temporary entities, if any, which have a common key definition data therein, among the created temporary entities into one entity, and to create a normalized entity. The entity type of the created normalized entity is then set. Moreover, the first matrix table showing the correspondence between the created normalized entity and the data is created, and the second matrix table showing the relationship between the created normalized entities is created on the basis of the first matrix table and a table which predetermines the relationship between entities according to their entity type. The E-R diagram is created on the basis of the second matrix table. Therefore, in accordance with the database design program, a database can be designed by a computer.
Moreover, since the second matrix table is created for every data, an E-R diagram on the basis of at least, one data from among the plurality of data, or an E-R diagram on the basis of the combination of two or more data can easily be created by the computer. As with the first aspect, the plurality of data including the key definition data and the data items corresponding to the key definition data may be input directly or via a network or the like. Moreover, this data may be data for/on a screen, a form, or a functional specification.
Further, in accordance with a thirty-fifth aspect of the present invention, in the database design program, at least one of the correspondence between the normalized entity in the first matrix table and the data, the relationship between the normalized entities in the second matrix table, the entity type of the normalized entity, and the correspondence between the key definition data and the data item forming the normalized entity can be altered. Accordingly, addition and/or deletion of data, contents modification of data, and the like can be processed.
In a thirty-sixth aspect of the present invention, there is a display method in which, when the E-R model is created on the basis of the data that includes the key definition data and data items corresponding to the key definition data, each data is displayed in a single display frame assigned to that data and a data title is displayed adjacent to the data frame.
In accordance with the thirty-sixth aspect of the present. invention, a display frame is provided for each data, the key definition data and data items corresponding to the key definition data of each data are displayed in the display frame that corresponds to the respective data, and the title of the data is displayed adjacent to the display frame. Accordingly, for each data, the key definition data and data items included in the data, can be easily checked.
For example, the key definition data and the data items may be displayed separately by entity in the display frame (1-column form).
Further, the display frame may be divided into a key definition data display column and a data item display column. Thus, the key definition data and the data items may be displayed in the key definition data display column and the data item display column, separately by entity (2-column form).
Further, the size of the display frame may be adjusted in accordance with the number of characters and/or the number of items of the key definition data and/or the data items which are displayed in the display frame.